Abstract
The broad Myiagi plain, which consists of the Quaternary system, extends to the east of Sendai City, and there are many hills (120-150m above sea level) which are formed out of the Neogene system around the urban district of Sendai, such as Dainenji-yama, Yagi-yama, Aoba-yama, Kita-yama etc. On the other side the western area of the city, the Miocene series can be seen in Natori-group and Akiu-group.These groupsconnect to the Ou mountains.
In October 1996, in an attempt to find a hot spring writers bored into theground at a point about 2km distant to the south of Sendai Station. Eventually we could find a hot spring at a depth of 1200m. It was a saline spring and the temperature of its water was 58°C. While writers were digging, also found the formation of old metamorphic rocks at depths of 800-1200m. The writers have ascertained that these metamorphic rocks belong to the Pre-Devonian period.
Until now it had been said that there was no hot spring in Sendai City, and no other formations prior to that of the Tertiary system had been found in the area. They think that these two discoveries will bring a new phase in the geological study of Sendai not only because they will be very useful for the future elucidation of the geological structure of the Sendai area, but also because they will give us an important clue in investigating the mechanisms of the outbreaks of earthquakes, landslides and slope failures in the area.
